The routine I posted is for FireRed. You simply assemble and insert as usual into freespace and then apply the byte edit in the comment in the ASM code.
Now for your first question. IDA is the Interactive Disassembler we use to turn the ROM into readable ASM code. This allows us to store metadata about locations among other things in IDBs (IDA Databases). It requires ASM knowledge to read and use, but I try to encourage newbies to learn while using it (as it seems to increase learning speed and understanding). We just trade these databases on the IRC for those interested. Come onto the IRC (see sig) if you want to learn more about it.
Now for your first question. IDA is the Interactive Disassembler we use to turn the ROM into readable ASM code. This allows us to store metadata about locations among other things in IDBs (IDA Databases). It requires ASM knowledge to read and use, but I try to encourage newbies to learn while using it (as it seems to increase learning speed and understanding). We just trade these databases on the IRC for those interested. Come onto the IRC (see sig) if you want to learn more about it.